1. Field of the Invention
This invention relates to a removable lid for a cup and, more particularly, to a lid assembly which is used to form the lid. The lid of the present invention avoids inadvertent splashing which occurs due to unintentional movement of the cup.
2. Art Related to the Invention
Splash-proof lids for drinking cups are known. Typically, they comprise a round, removable cover which fits tightly over the top opening of a cup to prevent unwanted spillage of the contents of the cup while allowing the user to drink the contents of the cup even though the lid remains on the cup. To allow the user to drink the contents of the cup while the lid remains on the cup, both a drinking hole and an air hole are provided in the lid. Both holes are configured to prevent unwanted loss or spillage of the contents of the cup which occurs when the cup is unintentionally moved. Typically, such lids are used on disposable cups which the user takes on a train, a plane, in a boat, or in a car.
The drinking hole is usually positioned at the edge of the lid next to the side wall of the cup, while the air hole is positioned either centrally in the lid or along the edge of the lid next to the side wall of the cup, opposite the drinking hole.
One example of such a lid is taught in U.S. Pat. No. 4,322,014. In the ""014 patent, a splash-proof lid has both a drinking hole and an air hole wherein both holes have a baffle arrangement to prevent the liquid contents of the cup from exiting the cup. The baffle arrangement is such that the axis of the baffle, taken along the fluid flow lines, forms a straight line and does not follow the contour or radius of the exterior of the lid. The baffle arrangement in the ""014 patent is rather complicated.
In order to make the lid of the ""014 patent, two separate pieces are either molded separately and then subsequently glued, or the lid is molded as one unitary piece. Molding is obviously difficult and assembling the two pieces is time-consuming.
Another example of a splash-proof lid is taught in U.S. Pat. No. 4,394,928. Here a special cup having a ledge functions with the lid to form a curved channel through which liquid flows to the drinking hole. This has the advantage of a one step molding process, but requires a special cup to allow the lid to function.
There is a need for a simplified design for a splash-proof lid which can function with a conventional disposable cup.
A simplified lid assembly for making a splash-proof lid for a cup has now been discovered. The lid is intended to be disposable and for use with disposable drinking cups such as the type used for coffee, tea, etc. The lid has an air hole, a drinking hole and is designed to avoid spillage of the contents of the cup through the drinking hole and the air hole.
It has been discovered that the jiggling or unintended movement of the cup causes a wave to form on the surface of the liquid and to travel back and forth across the surface of the liquid crashing against the side walls of the cup. When the wave hits the side walls of the cup, it splashes out of the drinking hole or the air hole when the air hole is positioned next to the side wall of the cup. Thus, it is the movement of the waves on the surface of the liquid in the cup and its crashing against the side wall that causes the splashing and the spillage of the liquid.
It has also been found that when the air hole is made small and positioned in the center of the lid that splashing or spillage due to the wave through the air hole does not occur. Furthermore, it has been found that when the air hole is made rather small compared to the drinking hole, that the air hole will still function to allow liquids to flow out of the drinking hole and air in through the air hole. Thus, in the present invention, the air hole is positioned in the center of the lid and made relatively small compared to the drinking hole.
To avoid spillage out of the drinking hole, an arched tube is employed in fluid communication with the drinking hole. The arched tube of the present invention blocks the wave from crashing directly into the drinking hole and redirects the liquid back into the cup to prevent spillage of the contents of the cup through the drinking hole.
The arched tube extends above and below the planar surface of the lid so as to form a chamber. The drinking hole is positioned in the top of the tube and the top of the tube rises above the planar surface of the lid. The bottom of the tube extends below the planar surface of the lid and contains inlets through which the contents of the cup travel to reach the drinking hole. The arched tube follows the curvature of the lid, is centered on the drinking hole, and is in fluid communication with the drinking hole. The arched tube is formed along the edge of the lid and has a plurality of inlets to allow the liquid contents of the cup to travel into the tube. The inlets can be in the bottom of the tube, in the end walls of the tube, or both. The drinking hole is positioned in the top of the tube to allow the liquid contents to flow from the cup through the tube and into the user""s mouth. The radius of the tube is less than the radius of the lid and the radius of the tube is concentric with the radius of the lid. The lid itself has an engaging periphery to allow it to engage with the rim of a cup and become removably affixed to the rim of the cup. In this way, the lid of the present invention fits a conventional disposable cup and no special cup must be employed with the lid of the present invention.
It has been discovered that the lid of the present invention can be easily made in a one step molding process from a unique lid assembly which is disclosed herein. The lid assembly is made up of two pieces, one piece being the disc that makes up the majority of the lid while the other piece is a bottom section which forms the bottom portion of the arched tube and a portion of the engaging periphery. The disc and the bottom section are rotatably connected to one another along their peripheries such that the lid is assembled by rotating the disc and the bottom section together. In the molding operation, the disc and the bottom section form one, essentially planar, element.
Broadly, the splash-proof lid for a drinking cup in accordance with the present invention comprises:
a circular disc having a snap fitting periphery for engagement with a cup rim;
an air hole in said disc which is positioned in the center of said disc;
an arched tube adjacent said snap fitting periphery, said tube having a radius that is concentric with the radius of said disc and less than the radius of said disc, said tube having a top portion which is above the top surface of said disc and a bottom portion which is below the bottom surface of said disc;
a drinking hole in a top wall of said tube, said tube centered on said drinking hole, said air hole being smaller than said drinking hole; and
at least two inlets in said tube positioned in said bottom portion of said tube, such that said inlets are in fluid communication with said drinking hole to allow a user to drink through the lid when the lid is placed on top of a drinking cup.
Broadly, the splash-proof lid assembly for making a lid for a drinking cup in accordance with the present invention comprises:
a circular disc having a periphery;
a first snap fitting periphery portion extending around a first portion of said periphery, said first snap fitting periphery portion absent from a second portion of said periphery;
a tube top portion with a drinking hole therein, said tube top portion positioned adjacent to said periphery at said second portion of said periphery, said tube top portion rising above the top surface of said disc;
an air hole positioned in the center of said disc;
a bottom section having an arcuate side, said bottom section having a second snap fitting periphery portion adjacent said arcuate side, and a tube bottom portion having at least two inlets therein, said tube bottom portion adjacent said second snap fitting periphery portion,
said bottom section rotatably attached to said disc along said periphery of said disc such that when said bottom section is rotated under said disc, said second snap fitting periphery portion is positioned in said second portion of said periphery, said tube bottom portion aligns with said tube top portion to form an archede tube in said lid, said inlets are in fluid communication with said drinking hole, and said first snap fitting periphery portion and said second snap fitting periphery portion for a complete snap fitting periphery of said lid.
Preferably, the inlets are in the bottom wall of the tube, however, the inlets can also be in the end wall of the tube, provided they are in the end wall of the bottom portion of the tube, i.e. below the bottom surface of the disc.
Preferably, the arched tube forms an angle of about 30 to about 60xc2x0 with respect to its radius.